Calling-device attachment



May 22,1923. 1,455,998

F. W. FAHRENFELD CALLING DEVICE ATTACHMENT Filed May 1 1920 Fred.FahrEfiTE'Zd.

Y 2 of the calling device.

Patented May 22, I923.

FREDERICK J7. FAI-IBENFELD, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATICELEG- TRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

CALLING-DEVICE ATTACHMENT.

Application filed May 1, 1920. Serial No. 378,242.

To all 10/201)? it may concern:

Be it known that I, FREDERICK IV. FAHBENFELD, a citizen of the UnitedStates of America, and a resident of Chicago, Cool;- County, and Stateof Illinois, have invented certain new and useful Improvements inCalling-Device Attachments, of which the following is a specification.

My invention relates in general to an attachment for a calling deviceand more specifically to a calling device ring or protecting casingwhich is adapted to be applied to a standard calling device to protectthe same. Y

Among the objects of 'my invention are to provide an easily attached andeasily removable protecting ring or case for a calling device dial whichmay be attached either only for shipment or while the dial is in use andeffectually prevents the usual knocks or blows, to which the device maybe subjected, from bending the finger hole dial of the device orotherwise defacing or damaging the device.

This is especially useful when the calling device is to be used by anoperator whose device is usually mounted in the handiest place for useand therefore where it is often likely to receive a number of severeknocks while the operator changes plugs in putting up connections. As iswell known to the art, the finger hole dial of the common type ofcalling device is pivoted at its center point and its outer edge or rimis considerably weakened by having the finger holes therein, the holesbeing used to rotate the dial in transmitting impulses. It will be seenalso that any blow on the rim of the finger hole dial is likely to causeconsiderable damage, either by defacing the same or by bending eitherthe dial or its pivot post so as to render its free rotation impossible.

In. the drawings I have shown in Figures 1 and 2 the rin clamped orsprung into position on the ca ling device and in Figure 3, I have showna perspective view of the protecting ring showing how it is formed tofit on the calling device.

The ring 1 of my invention is formed of steel, preferably blackenameled, and being open at one side to allow it to be forced apartsufficiently to snap it over the plate In the front view (Fig. 1) may beseen the upper edge of the ring lying just outside the edge of thefinger hole dial 3 and fitting closely around the finger stop 4.

Figure 2 is a side view of only the essential parts of standard callingdevice, with the ring out in half and shown in cross section This figureshows how the curved portion 5 of the ring fits over the back plate 2 ofthe calling device to hold the ring in position.

In Figure 3 the shape of the ring may be clearly seen, showing the innerand outer surfaces of the curved portion 5 and the opening 6 which isjust large enough to fit over the finger stop 4: when in position. Itwill be understood that the inner diameter of the ring above theenlarged or curved surface 5, is smaller than the diameter of the plate2 sothat the ring must be sprung outward in order to be attached.However, the plate 2 fits snugly into the curved portion 5 and is thereheld by the projecting surface 7 against movement.

In Figure 2 it will be seen that the upper or front edge of the ringlies just back of and a slight distance away from the outer front edgeof the finger hole dial, so that the dial may rotate freely and may yetbe protected from damage.

Having described the features of my invention what I consider to be newand desire to have protected by Letters Patent will be pointed out inthe appended claims.

What I claim as my invention is:

1. A tensioned protecting ring for a calling device, formed from steeland having a groove adapted to engage the outer edge of said deviceunder its own tension, to protect the finger-hole dial and prevent thebending or damaging of said dial.

2. In a calling device having a plate and a finger hole dial pivotedtherein, a removable casing or protecting ring tensioned to clamptightly about said plate and in such a position as to protect the dialfrom accidental blows,

3. In a calling device having a plate and a finger hole dial pivotedtherein and rotatable about an axis, a finger stop for limiting themovement of'the dial, and adetachable ring or casing formed of steel andadapted to be sprung into place around saidplate and being held in placeby the plate and the finger stop, said ring projecting up to and aroundthe free edge of the finger hole dial to protect the same Withoutinterfering With its operation.

4. In a calling device having a supporting plate carrying rotatablefinger hole dial,

- a finger stop, a ring formed of spring steel and having a concavesurface on the inner side thereof adapted to fit snugly over said plateand cut out portions in-said ring which fit over the finger stop toprevent the ring from slipping.

5. A protecting ring for a calling device, which is removable and isheld in place only by its own tension said ring lying around the outeredges of the finger hole dial to protect the same.

6. A protecting ring for calling device formed of heavy spring steel andhaving an opening in one side thereof Which permits its being sprungopen to be attached or removed troin the calling device.

7. A protecting ring for a calling device "formed of heavy spring steeland having an opening in one side thereof which permits its being sprungopen to, be attached or removed from the calling device, said openingbeing formed to fit snugly over the finger stop of the dial to hold thering in place.

8. In a calling device having a supporting plate carrying a rotatabledial and a finger stop, a protecting rim of steel adapted to be sprunginto position around said plate with its forward edge lying just outsideand around the outer edge of the dial,- and held there solely by its owntension.

Signed by me at Chicago, Cook County, Illinois, this 26th day of April,1920.

FRED. W. rnHnnNrnLD.

